214 APvT. II. A. IZÜKA : 



Body elongate, slightly tapering anteriorly, and more dis- 

 tinctly so posteriorly. Segments numbering 140-160 ; length 185- 

 220 mm., and breadth 6-6.5 mm. including parapodia at the hind 

 end of the anterior body third. Colour pearl-gi'ay with pinkish 

 iridescence. Dorsum convex. Ventral surface with a median 

 groove, wliicli splits into two in front behind the central promi- 

 nence and runs forwards one on each side to terminate at the 

 mouth. The parts in the fork is marked by a close series of 

 longitudinal furrows. 



Prostomium rounded in front ; eyes absent ; two papillae on 

 the posterior parts of prostomium. 



Proboscis in extrusion a massive pinkish iridescent organ 

 shaped like a pear, with 22 rows of distal papillœ, there being 

 usually 5 and occasionally 6 papillae in each row ; each lip of 

 j)roboscis with 10 forked papillae and a median simple papilla. 



Parapodium with a large fan- shaped dorsal lamella projecting 

 like a crest from the posterior border of dorsal ramus, having 

 greatest vertical diameter in the distal parts. The fleshy base of 

 parapodium, with the posterior part of which that lamella is 

 continuous, slopes from above downwards and outwards, and 

 terminates in a rounded lobe above the cirrus. Immediately below 

 the lamella is the short tapering dorsal cirrus, followed after an 

 interval by the externally coiled branchial process. A semicircular 

 flap lies over the base of the branchial process anteriorly, it being 

 the inferior termination of the flattened lamina between two rows 

 of bristles. Ventral ramus with a large, broadly lanceolate and 

 pointed lamella continuous with a fleshy lobe of the ramus ; 

 ventral cirrus of a moderate size, slightly flattened and conical. 



Setose bristles have terminal blade with a close series of 

 fine spikes. Beyond the serrated parts the bristle extends as a 



